Human and animal cells under influence of different lighting and stimulus

Circadian rhythms, are the basis of homeostasis of organisms like human and other mammals. Violation of circadian rhythms leads to the development of pathological conditions and severe course of preexisting pathologies. For example some work with B16-F1O cells (B16) has shown that molecules like opsins, Circadian Locomotor Output Cycles Kaput (CLOCK) and clock genes are changed after a white light pulse (WLP). Like this, melanopsin (OPN4) and rhodopsin (OPN2) through UVA irradiation induced B16 pigmentation. Thus, heat shock reduces secreted rhodopsin expression in normal Melan-a melanocytes, while the opposite effect is found in malignant B16 cells. In both cell lines UVA radiation increases the expression of melanopsin and melanin, interfering with several clock genes, and also increasing the DNA repair enzyme xeroderma pigmentosum, complementation group A (XPA). Furthermore, B16 are more responsive to UVA radiation when compared to normal cells. Thereby, opsins are involved in animal camouflage. And their functions in humans involve different wavelengths, for example in skin the keratinocyte differentiation by (410 nm) involved cone opsin (OPN1) and rhodopsin (OPN2), like this in epidermal keratinocytes irradiation by (447 nm) accelerates closure in wound-healing and violet light (415 nm) induced hyperpigmentation. Furthermore, in B16 cell culture certain wavelengths induce proliferation or inhibition like signs of apoptosis and necrosis. Finally understanding the response of opsins and clock genes to different wavelengths in the skin, we could attribute a therapeutic of photobiomodulation (PBM) to approach various dermatological conditions, such as psoriasis, atopic dermatitis, hair growth, wound healing and tissue regeneration.